A backshell is a component that is designed to be placed around that portion of a connector which contains the facilities for attaching electrical wires or cables to the connector. A backshell may also be referred to as a hood. A backshell may be designed to provide the accommodations between an electrical cable clamping device and an electrical connector shell. It may further include the clamping device. A backshell may alternatively be used to attach fiber optic cables to a fiber optic connector. It may be used for shielding the connector and cable against electromagnetic interference, mechanical damage, or physical damage due to environmental conditions.
A backshell is used to shield the cable connection points of the inter-connecting cable and the connector. Some backshells include a cable clamp to secure the cable to the backshell and connector. A grommet that is sized to the outside diameter (OD) of the cable may also be used.
A basic feature of the backshell is to provide a protective enclosure for routing cable from the connector location to conduit, cable channels, bulkhead access, tie-down points, etc. In order to facilitate the routing of the cables, backshells are typically designed for one of three types of cable exit angles:
straight, wherein the cable exits in-line with the cable/connector longitudinal axis;
forty five degree wherein the cable exits at forty five degree angle relative to the cable/connector longitudinal axis; and
ninety degree wherein the cable exits at ninety degree angle relative to the cable/connector longitudinal axis.
Backshells for military and aerospace connectors are typically designed for a particular military specification (Mil Spec) type or specific family of connector types. The backshells attach to these various connectors by way of accessory threads and teeth or splines on the rear of the connectors to lock them in place and prevent rotation. These threads and attachment configurations often vary between the various connector types and as a result, the backshells are not usually interchangeable between these different families of connectors.
Other features common to backshells are to providing electromagnetic interference/and/or radio frequency interference (EMI/RFI) protection by way of conductive metal shells or conductive plating, environmental protection, and providing strain relief by way of a cable clamp mechanism at the rear of the backshell.
The cable clamp mechanism may be unique to a particular application or connector backshell assembly. The cable clamp mechanism can serve multiple purposes. It can be used to capture the strain member of a cable (typically Kevlar fibers) or it can provide an attachment point for cable shielding to continue the EMI/RFI protection from cable to backshell to connector. The cable exit portal may also provide an attachment point for a variety of cable conduits or tubing.
In the current backshell designs, the desired cable exit angle is attained by way of a different and unique connector backshell assembly for each of the cable exit angles. Changing the cable exit angle by changing a backshell may be complicated and sometimes unfeasible in a pre-existing cable assembly and not something easily accomplished in the field.
Another drawback of current backshell designs is that they are usually a one piece shell design. This does not allow for the backshell to be opened up to provide access to the rear of the connector for servicing of the cable terminations. The entire backshell may have to be disconnected and moved up the cable away from the connector.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.